Ongoing DRM tests at 86.5 MHz in Copenhagen - 2022

I came across an interesting news report recently about an Digital Radio Mondiale (DRM) test that is currently taking place on 86.5 MHz in Copenhagen, the capital of Denmark.

While several countries have DAB systems up and running, some are carrying out test in or around Band 2 (88-108 MHz) and seeing if digital DRM signals could co-exist with analogue FM signals.

The DRM test in Copenhagen started on the 13th of October 2021 and runs until the 1st of August 2022. There is an option of extending this to the 30th of August 2023.

This is a collaborative project organised by Open Channel, an independent Danish network operator in Copenhagen, with Canadian Nautel (transmitter), German RFmondial (DRM modulator & measuring instruments) & Fraunhofer IIS (Content server) and Swedish Progira (network planning).

The project is supported by Gospell, NXP, partners in Denmark and other non-DRM Consortium members like Bauer Media (supplying content) and Kathrein (antenna).

The frequency allocated is 86.5 MHz and with a bandwidth of 200 kHz, which makes room for two DRM signals. Each DRM signal has a capacity of 186.4 kbps (16QAM, CR 5/8) and accommodates three audio channels and multimedia services, so for the 200 kHz a total of six digital radio stations can thus be broadcast. Further down the line there are ambitions to involve the Öresund region (commonly known in English as the Sound, a strait which forms the Danish–Swedish border) and possibly collaborate with another FM station on the Swedish side.

The height of the antenna is 88m and the terrain elevation is 8m (more details below). In phase 1, Open Channel will test single DRM channel with 120 Watt ERP. The coverage probability for mobile reception in Greater Copenhagen is illustrated in the picture below...

The trial on the 86.5 MHz frequency has also been approved by the Swedish Post and Telecom Agency. The fact that the experiment is done a bit below the regular FM band (band II 87.5-108 MHz) is due to the fact that there is no space in this dense region. The new receivers for FM/DRM can handle 64-108 MHz.

“We are working on expanding the FM band in Denmark from 85 – 87.5 MHz, so that the Danish FM band goes from 85 to 108 MHz and thereby create more space to introduce digital radio on the FM band”... says Kenneth Wenzel, project manager and director of Open Channel.

“This DRM field trial offers a unique opportunity to showcase the versatility of DRM-FM by packing two DRM signals within a single FM channel allocation demonstrating optimal spectral efficiency for DRM using a Nautel VS transmitter.”... says Philipp Schmid, CTO at Nautel.

Source... https://www.drm.org/drm-for-fm-in-the-heart-of-europe/

New DRM tests on 954 kHz planned from the Czech Republic in 2022

It was announced recently that České Radiokomunikace (CRA) in the Czech Republic has obtained a license from the Czech telecoms regulator (ČTÚ) to conduct a DRM test on 954 kHz in the city of České Budějovice in the south of the country.

The transmitter will have a power of just over 3kW which means it may be heard across Europe at night. The 954 kHz is one of the medium wave frequencies where the (AM) programs ČRo Dvojka and ČRo Plus were broadcast until the end of 2021.

CRA wants to use the test, among other things, to determine the scope and energy efficiency of broadcasting in the DRM standard. Both the 16 QAM and 64 QAM, the two common modulation schemes in DRM, will be tested. The operator will use an existing Transradio medium wave transmitter into which they will integrate a digital modulator.

The DRM system has long been touted as the digital replacement for AM on the Medium Wave and Short Wave bands. In 2003 and 2006, the Czech public broadcaster ČRo conducted a series of DRM tests on medium and short wave so these new tests should be seen in that light.

DRM has gained a foothold in countries like India but the take up has been slow elsewhere in the world.

New Android App for decoding DRM digital radio broadcasts

 

On the 13th of April 2021, a company named StarWaves announced the release of a new Android app called DRM SoftRadio. The app allows a user of a Software Defined Radio (SDR) to listen to any DRM digital broadcasts on an Android smartphone or tablet.

DRM or Digital Radio Mondiale is the global digital radio standard used for digital transmissions on medium wave and short wave in several countries. 

Some of the features...

Languages: English, German, Simplified Chinese

Convenient frequency tuning and DRM Service selection

Journaline, DRM’s advanced text application, allows to interactively browse through latest news, sports and weather updates, programme background information and schedules, distance learning/RadioSchooling text books, travel information, and much more

Free tuning to any DRM broadcast frequency

Supports all DRM frequency bands – from the former AM bands (LW/MW/SW) to the VHF bands (including the FM band), depending only on RF dongle functionality

Graphical spectrum view to check the signal on the tuned frequency

For live reception, an SDR RF dongle must be connected to the device’s USB port (with USB host functionality). The following SDR RF dongle families are currently supported, along with a range of specifically tested models:

Supported SDR receivers...

Airspy HF+ family: Airspy HF Discovery, Airspy HF+ (Dual Port). (Note: Airspy Mini and R2 are NOT supported.)

SDRplay family: SDRPlay RSP1A, SDRPlay RSPdx, SDRPlay RSPduo, SDRPlay RSP1, SDRPlay RSP2, SDRPlay RSP2pro, MSI.SDR Panadapter (Note: SDRPlay family support on Android is currently limited to the 32-bit version of this app.)

RTL-SDR family: The experimental support for RTL-SDR based RF dongles requires that you manually start the following separate tool before opening this app (on standard port ‘14423’): The app ‘SDR driver’ can be installed from the Google Play Store and other Android app stores.

Analysis... While DRM (Digital Radio Mondiale) has been around as a digital radio standard since 2003, it has proved difficult to get accepted by broadcasters and the general public. Broadcasters were unwilling to use DRM due to a lack of suitable receivers and the public weren't interested because there were a lack of DRM transmissions.

That has changed of late with the introduction of DRM transmissions in the medium wave band in India. Considering its population, it is assumed that this will kick off the development of cheaper DRM receivers.

While SDR receivers are probably used more by those interested in technology and radio rather than the general public, this new app does open up DRM transmissions to a whole new audience.

The app costs in the region of €5/$5 which is very modest for most SDR users.

It is my understanding that a Windows version is being developed by the company and this should be of interest to an even wider audience.

Links...

1) StarWave news release - 13th April 2021

2) Google Play Store

3) Official DRM website

Successful DRM tests on the FM band (88-108 MHz) in Russia

 

DRM (Digital Radio Mondiale) has long been touted as a possible replacement for the analogue AM and FM modes on the radio broadcast bands. The transition to digital has proved problematic as broadcasters and listeners are happy to continue with the status quo, especially on the 88-108 MHz FM band.

While many countries have opted for DAB and DAB+ transmissions on the VHF Band 3 (175-225 MHz), some countries are looking at the option of using DRM transmissions in the spaces between the FM signals on the 88 to 108 MHz band.

From June to December 2019, a sixth month trial DRM transmission was carried out in the Russian city of St.Petersburg. The 800-watt DRM transmitter was on 95.7 MHz between the FM radio stations Studio 21 at 95.5 MHz and Comedy Radio at 95.9 MHz. 

The main audio source for the trial was the Comedy Radio, which was broadcasted simultaneously as an analogue FM service (3KW) and a DRM service (0.8KW). This allowed a direct comparison to be made between the analogue FM and DRM coverage.

The results of the trial were publish in December 2020 in a paper titled..."RESULTS OF THE DRM SIMULCAST FIELD TRIAL IN FM BAND IN THE RUSSIAN FEDERATION... June to December 2019"

Some of the main conclusions were as follows...

The trial has shown that for DRM Simulcast with frequency offset of 150 kHz, DRM digital signal does not interfere with the analog FM signal at a power difference up to -10 dB.

For a frequency offset of 200 kHz, the digital DRM signal does not interfere with the analog FM signal at any power values that the transmitter could provide.

Because DRM Simulcast allows to keep FM broadcasting and launch terrestrial digital radio broadcasting in the same frequency range. DRM multiplexes can be launched between existing FM radio stations without interfering with them. To do this, it can use one transmitter and existing combiner and antenna system.

20:1 Digital Power Advantage... In separate tests done in Indonesia, it was claimed that six test points covered by the 1 kW transmitter (FM) could be served with only 50 watts of DRM power. “In testing a simulcast broadcast using 1 kW and 800 Watt with spacing distance 150 kHz between the middle frequency FM and DRM, the measurement showed no interference between FM and DRM. The DRM quality was at least equally good to FM, but the sound quality of DRM was even better than FM.”

In an article titled "Use DRM on India’s FM Band", the chair of the of the India chapter of the DRM Consortium Yogendra Pal stated..."Using DRM, in the allocated 200 kHz bandwidth, a broadcaster can transmit up to six high-quality audio services along with a host of value-added services and Emergency Warning Functionality (EWF). All digital services work without disturbing the existing analog FM services."

He also claimed that mobile phones that used for listening to analogue FM transmissions can also be used for listening to DRM transmissions as long as manufacturers allow the DRM app to access the baseband digital output.

"DRM standard can be supported natively on all mobile phones based on the already available tuners for analog FM reception. No additional hardware and, therefore, no additional design or component cost is required to enable DRM digital FM support on these phones.

The DRM App for mobile phones has already been developed and demonstrated by a number of organizations. Only the mobile phone manufacturers need to provide access of the baseband digital output. "

In summary... A lot of the information shown above is from the DRM industry who obviously want to push the new digital standard. However, the tests of using DRM on Band 2 (88-108 MHz) do suggest that there are more options than just setting up a new digital broadcast band elsewhere on the VHF spectrum. There are spaces in the FM band (88-108) and DRM can utilise those gaps.

Band 2 also tends to have mush better mobile coverage than the higher VHF bands around 200 MHz which are used for DAB transmissions and many listeners already have dedicated aerials for the 88-108 MHz band.

Transmitting DRM on Band 2 is also an attractive option for broadcasters in that they can use the same antennas and infrastructure. It provides them with an obvious path to gradually migrate to digital only services in the future.

Cambridge Consultants announce low cost DRM receiver design

DRM or Digital Radio Mondiale has long been touted as the digital solution for Medium Wave and Short Wave broadcast radio with higher efficiencies and less noise. There have been tests for well over a decade but very few adopters until now.

India now has 35 DRM transmitters covering the sub-continent with a potential audience of about a billion people. There is however still a serious issue regarding the high cost of receivers.

A company called Cambridge Consultants have now announced a prototype of a DRM design which will cost $10 or less. If they are successful, it could be a game changer for digital radio.

This is from their press release... "Cambridge Consultants has just held its annual Innovation Day, where we throw open our doors to industry leaders and reveal future technology. One of our highlights was the prototype of a DRM design that will cost ten dollars or less to produce, addressing that vital need for information by the 60-ish per cent of our global population that doesn’t have internet or TV. It’s low power, so can run from solar or wind-up.

This design will be ready in 2020, available for any radio manufacturer to licence and incorporate into its own products. "

More info HERE

DRM tests from Hungary on 26 MHz - June 2019 to June 2020

Normally news items about DRM (Digital Radio Mondiale) tests on the short wave bands are of little interest to me except that this one is unusually at 26 MHz!

Avion DRM receiver

The Budapest University of Technology started a 1-year DRM test on the 1st of June 2019 and it will run until the end of May 2020.

The transmitted content is a 24-hour program, played out in a loop, compiled by the media partner of the project, Radio Maria.

They are transmitting on a frequency of 26.060 MHz with 100 watts into a 5/8 vertical.

Additional info..."The current short wave DRM transmission performed from the university has two main objectives: partly to demonstrate the value-added possibilities of DRM (xHE-AAC coding, slideshows and Journaline advanced text services accompanying the audio content), and partly to provide an opportunity for receiver manufacturers to test their products in real life. Since this is not a public or commercial service, the modulation parameters (transmission mode, SDC and MSC constellations, interleaving depth, etc.) can be freely changed at any time. Developers are, therefore, welcome to perform field tests with their devices in Budapest working in close co-operation with the broadcasting team of the Department of Broadband Infocommunications Systems and Electromagnetic Theory of the Budapest University of Technology. 

The landscape of the Hungarian capital is particularly interesting because the town is partly built on a flat area, partly on hills. The two sides are separated by the river Danube and are exhibiting various interesting wave propagation phenomena."

Looking at the display above, it looks as if the DRM signal is about 6 kHz wide.

The technical parameters of the demonstration broadcast in Budapest, Hungary, are as follows:

Frequency: 26060 kHz
EIRP: approximately 100 W
Antenna: 5/8 l monopole
Transmission time: 24/7

Thoughts.... Under Sporadic-E conditions, this should be heard around Europe. It has been heard already in the Netherlands so it should be possible.

As most people don't have DRM receivers, have a listen to Radio France Internationale on 3.965 MHz at night and you will hear a good strong DRM signal. If you listen on AM or SSB, you will get a good idea of what a DRM signal sounds like. If you hear the same type of signal on 26.060 MHz then it is very likely to the the test transmission from Hungary.

Links...
1) https://www.drm.org/

Addendum...
1) In response to this blog post, Rob PE9PE suggests the use of an online SDR to listen to the 26 MHz frequency... http://websdr.ewi.utwente.nl:8901/ and https://sdr.hu/

I wonder if there is an online DRM receiver in Europe???

2) Thanks to Bas PE4BAS for the info about the DREAM programme which can decode DRM signals. Info... https://www.drm.org/pc-based-receivers-and-software/

3) Info on 26 MHz from the DRM Handbook (Feb 2019)...

FCC petitioned to open up 45 to 50 MHz for DRM+ broadcasts in the USA

Currently most of the terrestrial radio stations in the USA broadcast either on the AM band from 540 to 1700 kHz or on the FM band from 88 to 108 MHz. At the end of September 2018, the FCC announced that there were 4,464 stations on AM and 10,867 stations on FM [1].

Due the crowded nature of the existing bands, it has been hard to introduce new digital radio formats.

DRM or Digital Radio Mondiale is a digital format designed to replace existing AM transmissions with clearer audio and with just 20% of the power. DRM+ is the format for VHF.

WRNJ Radio co-owner Larry Tighe has now filed a petition for rulemaking with the FCC, asking that the 45 MHz to 50 MHz band on the VHF spectrum be reallocated for DRM+ transmissions.

In a statement, Tighe said... “The 45–50 MHz band was allocated to two-way radio users in business and government, who have since migrated to higher bandwidths where they can use handsets with smaller antennas. As a result, this spectrum is extremely quiet right now. WRNJ monitored this bandwidth for an extended period of time, and heard very few distant signals.”

“There were 660 TV stations between Channels 2 and 7 before the transition to UHF for HDTV. There are now only approximately 60 TV stations in the USA on those old VHF channels. There is plenty of spectrum to share with a new service, i.e., DRM+ or any modulation, if the FCC really wanted to move AMs.”

Even though the DRM standard has been around for over a decade, it is only recently that it has begun to make serious inroads to the broadcasting scene with India, China and Russia showing an interest. One of the current problems is the high cost of DRM receivers which is prohibitive to consumers in developing countries.

Obviously if the USA opted for a new DRM+ allocation, it would give the format a huge boost. If it turned out to be the 45 to 50 MHz allocation then it raises the possibility of long distance reception by means of Sporadic-E during the summer months or via F2 propagation around the peak of the sunspot cycle.

More info in the links below.

Links...
1) FCC stats for the number of AM and FM stations at the end of Sept 2018
2) https://www.radioworld.com/tech-and-gear/u-s-based-shortwave-broadcasters-eye-digital
3) Previous post - Russia proposes to use DRM on 65.9-74.0 MHz

Russia proposes to use DRM on 65.9-74.0 MHz

On the 11th of September 2018, it was reported that the Russian Federation proposes to use the digital DRM+ standard for broadcasting on the  the radio frequency bands 65.9-74 MHz and 87.5-108 MHz.

While this move may not have much of an issue here in Ireland, it has the potential of being a major source of interference to radio amateurs using the 4 metre band (70 MHz) in central and eastern Europe. As 'Secondary Users' of this part of the spectrum, radio amateurs have no choice but to live with any interference, especially during the Summer Sporadic-E season.

The 65.9 MHz to 74 MHz spectrum has been used up to now for analogue FM transmissions in Russia and some adjacent countries. Over the last 20 years, the general trend has been to close these low band VHF transmitters and move them instead to the usual 88 to 108 MHz band. It seemed as if the 65.9 to 74 MHz band might eventually close but this new digital DRM allocation will see it being put to a new use.

This highlights the fact that while extensive parts of the low band VHF spectrum were allocated to the Amateur Radio Service in Ireland, that is very unlikely to happen elsewhere in Europe.

From Google Translate...